GO:0009361 succinate-CoA ligase complex (ADP-forming): Components, Assembly and Research Methods, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0009361 describes the ADP-forming succinate-CoA ligase complex, a heterodimeric enzyme that converts succinyl-CoA to succinate while generating ATP.
• The complex is most commonly found in bacteria but also occurs in mitochondria of eukaryotes and is central to the TCA cycle.
• Deficiency of the ADP-forming succinyl-CoA synthase activity causes encephalomyopathy and mitochondrial DNA depletion.
• The beta subunit (SUCLA2) promotes stress granule assembly and drives cancer metastasis by regulating redox balance.
• Mutations in SUCLA2 and related genes are linked to hereditary peripheral neuropathies and mitochondrial oxidative enzyme impairment.
• Studying this complex requires knockout, point-mutation, knock-in, and overexpression models combined with metabolic and proteomic readouts.
Description
The succinate-CoA ligase complex (ADP-forming), annotated as GO:0009361, is a heterodimeric enzyme that catalyzes the reversible conversion of succinyl-CoA to succinate and CoA, coupled to ATP formation. This complex is a key component of the tricarboxylic acid (TCA) cycle and is most usually found in bacteria, though it also functions in eukaryotic mitochondria. Researchers study GO:0009361 because its activity directly links central carbon metabolism to cellular energy status and because its dysfunction is associated with severe human disorders, including encephalomyopathy and mitochondrial DNA depletion. The complex has also emerged as a regulator of redox homeostasis and cancer metastasis through its beta subunit. Understanding its structure, catalytic mechanism, and regulation is therefore essential for both basic metabolism research and translational disease studies.
succinate-CoA ligase complex (ADP-forming) At A Glance
| GO ID | GO:0009361 |
|---|---|
| GO term | succinate-CoA ligase complex (ADP-forming) |
| Ontology | cellular_component |
| Synonym | succinyl-CoA synthetase, ADP-forming |
| Major function | Hydrolyzes succinyl-CoA to succinate and CoA, forming ATP in the TCA cycle |
| Subunit composition | Heterodimer of alpha and beta chains |
| Taxonomic distribution | Most usually found in bacteria, but not limited to bacteria |
| Pathway context | Tricarboxylic acid (TCA) cycle |
What Is GO:0009361?
GO:0009361 refers to a heterodimeric enzyme complex composed of an alpha chain and a beta chain that functions in the TCA cycle. It hydrolyzes succinyl-CoA into succinate and CoA, and in doing so forms ATP. The complex is most usually found in bacteria but is not limited to them. Its synonym is succinyl-CoA synthetase, ADP-forming.
Why Is succinate-CoA ligase complex (ADP-forming) Important in Cell Biology?
The succinate-CoA ligase complex (ADP-forming) is important because it provides a direct enzymatic link between the TCA cycle and ATP generation, and its dysfunction has been documented in human mitochondrial disease. Deficiency of the ADP-forming succinyl-CoA synthase activity is associated with encephalomyopathy and mitochondrial DNA depletion, and mutations in the SUCLA2 gene cause impaired activity of other mitochondrial oxidative enzymes in skeletal muscle without mtDNA depletion. Beyond inherited disease, the beta subunit of this complex promotes stress granule assembly to regulate redox and drive cancer metastasis. These findings make GO:0009361 a focal point for studies of mitochondrial metabolism, redox biology, and cancer progression.
• Central to the TCA cycle by converting succinyl-CoA to succinate while forming ATP.
• Deficiency of ADP-forming succinyl-CoA synthase activity is linked to encephalomyopathy and mitochondrial DNA depletion.
• SUCLA2 deficiency causes impaired activity of other mitochondrial oxidative enzymes in skeletal muscle.
• The beta subunit promotes stress granule assembly and regulates redox to drive cancer metastasis.
• Mutations in mitochondrial-related nuclear genes, including SUCLA2, cause complex hereditary peripheral neuropathies.
• The complex is a target for understanding ATP-specificity and nucleotide binding in diverse organisms.
• It is relevant to metabolic reprogramming in cancer immune evasion.
• Its activity can be studied in both bacterial and eukaryotic systems, including cultured plant cells.
• Altered oxygen consumption and Complex I activity in fetal sheep with intrauterine growth restriction may involve mitochondrial enzymes like this complex.
• Provides a model for studying heterodimeric enzyme assembly and catalysis.
What Happens During succinate-CoA ligase complex (ADP-forming)?
Substrate binding and succinyl-CoA hydrolysis
In simple terms: The enzyme grabs succinyl-CoA and breaks it apart.
The complex binds succinyl-CoA and catalyzes its hydrolysis into succinate and CoA. This reaction is part of the TCA cycle and is coupled to the formation of ATP from ADP and inorganic phosphate. The heterodimeric alpha and beta chains together form the active site that accommodates succinyl-CoA.
ATP formation via substrate-level phosphorylation
In simple terms: The energy released from breaking succinyl-CoA is used to make ATP.
The hydrolysis of succinyl-CoA is energetically coupled to the phosphorylation of ADP to ATP. This is a substrate-level phosphorylation event, meaning ATP is generated directly from a high-energy substrate rather than through an electron transport chain. The ADP-forming nature of this complex distinguishes it from other succinate-CoA ligases that use GDP or other nucleotides.
Role in the TCA cycle and energy metabolism
In simple terms: This step keeps the TCA cycle running and supplies ATP.
By converting succinyl-CoA to succinate, the complex maintains flux through the TCA cycle. Succinate produced by this reaction can be further oxidized. The ATP generated contributes to cellular energy pools, especially in bacteria and in mitochondria where this complex operates. Deficiency of this activity disrupts mitochondrial energy metabolism and can lead to mtDNA depletion.
Redox regulation and stress granule assembly
In simple terms: The beta subunit also helps cells manage oxidative stress and form stress granules.
Beyond its canonical metabolic role, the beta subunit of the ADP-forming succinyl-CoA ligase promotes stress granule assembly to regulate redox balance. This function has been shown to drive cancer metastasis, linking the complex to cellular stress responses. This moonlighting function expands the biological importance of GO:0009361 beyond the TCA cycle.
Key Genes Involved in GO:0009361 succinate-CoA ligase complex (ADP-forming)
The following genes and proteins are experimentally linked to the succinate-CoA ligase complex (ADP-forming) or its subunits.
| Gene | Major Role | Research Relevance |
|---|---|---|
| SUCLA2 | Encodes the beta subunit of the ADP-forming succinyl-CoA ligase complex | Mutations cause encephalomyopathy, mtDNA depletion, and impaired mitochondrial oxidative enzymes |
| SUCLG1 | Encodes the alpha subunit of the succinyl-CoA ligase complex | Deficiency of ADP-forming succinyl-CoA synthase activity is associated with encephalomyopathy |
| SUCLG2 | Encodes a GTP-specific succinyl-CoA ligase beta subunit | Related to but distinct from the ADP-forming complex; useful for comparative studies |
| SUCLA2 (beta subunit) | Promotes stress granule assembly and regulates redox | Drives cancer metastasis |
| SUCLA2 (beta subunit) | Mitochondrial oxidative enzyme activity | Deficiency impairs other mitochondrial oxidative enzymes in skeletal muscle |
| SUCLA2 | Mitochondrial-related nuclear gene | Novel variants cause complex hereditary peripheral neuropathies |
| SUCLG1 | Mitochondrial-related nuclear gene | Novel variants cause complex hereditary peripheral neuropathies |
| NSUN2 | RNA methyltransferase with moonlighting function in metabolic reprogramming | Promotes cancer immune evasion via metabolic reprogramming involving succinyl-CoA-related pathways |
| Succinyl-CoA synthetase (plant) | ADP-forming succinyl-CoA ligase in cultured soya bean cells | Model for studying the enzyme in non-bacterial systems |
| Succinyl-CoA synthetase (Blastocystis hominis) | ATP-specificity of succinyl-CoA synthetase | Structural studies on nucleotide specificity |
| Mitochondrial Complex I subunits | Oxidative phosphorylation | Lower oxygen consumption and Complex I activity in fetal sheep with intrauterine growth restriction may involve succinyl-CoA ligase |
| SUCLA2 (beta subunit) | Redox regulation | Stress granule assembly and cancer metastasis |
| SUCLG1 (alpha subunit) | Heterodimer assembly | Essential for catalytic activity of the ADP-forming complex |
| SUCLA2 (beta subunit) | ATP formation | Substrate-level phosphorylation in TCA cycle |
| SUCLG2 (beta subunit) | GTP-specific ligase | Comparative studies on nucleotide specificity |
| Succinyl-CoA ligase (bacterial) | ADP-forming complex in bacteria | Model organism for structural and mechanistic studies |
| SUCLA2 (beta subunit) | Stress granule assembly | Links metabolism to stress response and metastasis |
| SUCLG1 (alpha subunit) | Mitochondrial DNA maintenance | Deficiency leads to mtDNA depletion |
How Is succinate-CoA ligase complex (ADP-forming) Regulated?
The succinate-CoA ligase complex (ADP-forming) is regulated at multiple levels. Its expression and activity are influenced by mitochondrial energy status and by the availability of substrates such as succinyl-CoA and ADP. In cancer, the beta subunit (SUCLA2) is regulated to promote stress granule assembly and redox balance, which supports metastasis. Deficiency of the complex can lead to compensatory changes in other mitochondrial oxidative enzymes, as seen in SUCLA2 deficiency. Additionally, metabolic reprogramming involving NSUN2 can affect succinyl-CoA-related pathways and immune evasion. The complex is also subject to regulation by oxygen consumption and Complex I activity, as observed in fetal sheep with intrauterine growth restriction.
succinate-CoA ligase complex (ADP-forming) and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| SUCLA2 | Encephalomyopathy and mitochondrial DNA depletion | Knockout in human cell lines or patient-derived fibroblasts |
| SUCLA2 | Impaired mitochondrial oxidative enzymes in skeletal muscle | Knockout in mouse skeletal muscle or myotubes |
| SUCLA2 | Hereditary peripheral neuropathies | Point-mutation knock-in in mice or iPSC-derived neurons |
| SUCLG1 | Encephalomyopathy and mtDNA depletion | Knockout in human cell lines |
| SUCLA2 | Cancer metastasis and redox regulation | Overexpression or knockout in cancer cell lines and mouse metastasis models |
Encephalomyopathy and mitochondrial DNA depletion
Deficiency of the ADP-forming succinyl-CoA synthase activity is associated with encephalomyopathy and mitochondrial DNA depletion. This condition typically presents with severe neurological symptoms and mitochondrial dysfunction. The complex's role in ATP formation and TCA cycle flux explains why its loss affects tissues with high energy demands, such as brain and muscle.
SUCLA2 deficiency and mitochondrial oxidative enzyme impairment
SUCLA2 deficiency in two siblings caused impaired activity of other mitochondrial oxidative enzymes in skeletal muscle without mitochondrial DNA depletion. This highlights that the complex can affect mitochondrial function through mechanisms beyond mtDNA maintenance. The study underscores the importance of SUCLA2 in coordinating mitochondrial energy metabolism.
Hereditary peripheral neuropathies
Novel variants in mitochondrial-related nuclear genes, including SUCLA2 and SUCLG1, cause complex hereditary peripheral neuropathies. These findings link the ADP-forming succinyl-CoA ligase complex to peripheral nerve degeneration. The clinical spectrum includes sensory and motor deficits, expanding the disease phenotypes associated with GO:0009361.
Cancer metastasis and redox regulation
The beta subunit of succinyl-CoA ligase ADP-forming promotes stress granule assembly to regulate redox and drive cancer metastasis. This moonlighting function connects the complex to cancer progression. Additionally, NSUN2 promotes cancer immune evasion via metabolic reprogramming that may involve succinyl-CoA pathways. These studies position the complex as a potential target in oncology.
From succinate-CoA ligase complex (ADP-forming)-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| What is the effect of SUCLA2 loss on TCA cycle flux? | SUCLA2 knockout cell lines (e.g., HEK293, HeLa) |
| How do disease-causing mutations affect complex assembly? | Point-mutation knock-in of SUCLA2 or SUCLG1 variants |
| Can the beta subunit be tagged to study stress granule localization? | Tagged knock-in of SUCLA2 with fluorescent protein |
| Does overexpression of SUCLA2 drive metastasis? | Overexpression in cancer cell lines followed by mouse xenografts |
| What is the role of the alpha subunit in mtDNA maintenance? | SUCLG1 knockout or knockdown in human fibroblasts |
| How does the complex respond to metabolic stress? | Knockout or overexpression combined with metabolic stress inducers |
How to Study the succinate-CoA ligase complex (ADP-forming) Process
| Method | What It Measures | Typical Application |
|---|---|---|
| 13C metabolic flux analysis | Flux through the TCA cycle and succinyl-CoA ligase activity | Comparing wild-type and mutant cells |
| Immunoblotting | Protein levels of SUCLA2 and SUCLG1 | Assessing mutation effects on subunit stability |
| Fluorescence microscopy | Stress granule assembly and localization | Studying beta subunit moonlighting function |
| Seahorse respirometry | Oxygen consumption and Complex I activity | Evaluating mitochondrial dysfunction |
| Proteomics | Global changes in mitochondrial enzymes | Identifying compensatory pathways in deficiency |
| CRISPR knockout screening | Gene essentiality and synthetic lethality | Finding modifiers of succinyl-CoA ligase dependence |
| RNA-seq | Transcriptional changes in metabolic pathways | Understanding metabolic reprogramming |
| Immunoprecipitation | Protein-protein interactions of the complex | Identifying binding partners and assembly factors |
Metabolic flux analysis
Metabolic flux analysis using 13C-labeled substrates can measure the activity of the succinate-CoA ligase complex (ADP-forming) within the TCA cycle. This method quantifies the conversion of succinyl-CoA to succinate and the associated ATP production. It is particularly useful for comparing wild-type and mutant cells.
Proteomics and immunoblotting
Proteomic profiling and immunoblotting can assess the expression levels of SUCLA2 and SUCLG1 subunits. These methods help determine whether disease-associated mutations affect protein stability or complex assembly. They are also used to evaluate compensatory changes in other mitochondrial enzymes.
Stress granule imaging
Fluorescence microscopy can visualize stress granule assembly promoted by the beta subunit of the complex. This approach links the metabolic enzyme to redox regulation and cancer metastasis. Co-localization with stress granule markers such as G3BP1 is commonly used.
Mitochondrial respiration assays
Seahorse extracellular flux analysis or high-resolution respirometry measures oxygen consumption and Complex I activity. These assays can reveal mitochondrial dysfunction caused by succinyl-CoA ligase deficiency. They are valuable for studying the impact of the complex on cellular energetics.
How CRISPR Can Be Used to Study GO:0009361 succinate-CoA ligase complex (ADP-forming)
Knockout
CRISPR knockout of SUCLA2 or SUCLG1 can abolish the ADP-forming succinyl-CoA ligase complex activity. This approach is used to model encephalomyopathy and mtDNA depletion. Knockout cell lines also help determine the complex's role in TCA cycle flux and stress granule assembly.
Point Mutation
Point mutations identified in patients with hereditary peripheral neuropathies can be introduced into SUCLA2 or SUCLG1 using CRISPR. These models help dissect the molecular consequences of specific variants. They are valuable for testing whether a mutation affects catalytic activity or complex assembly.
Knock-in
Knock-in of tagged versions of SUCLA2 or SUCLG1 allows visualization and purification of the complex. Fluorescent tags enable live-cell imaging of stress granule localization. Affinity tags facilitate proteomic identification of interacting partners.
Overexpression
CRISPR activation or lentiviral overexpression of SUCLA2 can drive cancer metastasis in experimental models. Overexpression studies help establish causality between the beta subunit and redox regulation. They are also used to study metabolic reprogramming in cancer immune evasion.
How EDITGENE Supports succinate-CoA ligase complex (ADP-forming) Research
Researchers studying succinate-CoA ligase complex (ADP-forming)-related genes often need to determine whether a candidate gene is causally involved in mitochondrial metabolism, disease pathogenesis, or cancer progression. EDITGENE provides a comprehensive suite of CRISPR-based services to enable these investigations.
Contact EDITGENE today to design your custom CRISPR model for succinate-CoA ligase complex (ADP-forming) research.
Frequently Asked Questions About succinate-CoA ligase complex (ADP-forming)
What is succinate-CoA ligase complex (ADP-forming)?
It is a heterodimeric enzyme complex that converts succinyl-CoA to succinate and CoA while forming ATP, and it is annotated as GO:0009361.
What genes are involved in succinate-CoA ligase complex (ADP-forming)?
The main genes are SUCLA2, which encodes the beta subunit, and SUCLG1, which encodes the alpha subunit.
What diseases are associated with GO:0009361?
Deficiency of the ADP-forming succinyl-CoA synthase activity is associated with encephalomyopathy and mitochondrial DNA depletion, and mutations cause hereditary peripheral neuropathies.
How is succinate-CoA ligase complex (ADP-forming) regulated?
It is regulated by substrate availability, mitochondrial energy status, and in cancer by stress granule assembly and redox signaling.
What is the role of SUCLA2 in cancer?
SUCLA2 promotes stress granule assembly to regulate redox and drive cancer metastasis.
Can CRISPR be used to study succinate-CoA ligase complex (ADP-forming)?
Yes, CRISPR knockout, point mutation, knock-in, and overexpression models are widely used to study its function and disease relevance.
What methods are used to measure succinate-CoA ligase complex activity?
Metabolic flux analysis, immunoblotting, fluorescence microscopy, and mitochondrial respiration assays are commonly used.
Is succinate-CoA ligase complex (ADP-forming) found in bacteria?
Yes, it is most usually found in bacteria but is not limited to them.
What is the difference between ADP-forming and GTP-forming succinyl-CoA ligase?
The ADP-forming complex uses ADP to form ATP, while GTP-forming variants use GDP to form GTP; they differ in nucleotide specificity.
How does SUCLA2 deficiency affect mitochondria?
SUCLA2 deficiency can impair other mitochondrial oxidative enzymes in skeletal muscle without mtDNA depletion.
Conclusion
The succinate-CoA ligase complex (ADP-forming), GO:0009361, is a critical heterodimeric enzyme in the TCA cycle that couples succinyl-CoA hydrolysis to ATP formation. Its dysfunction is linked to encephalomyopathy, mitochondrial DNA depletion, and hereditary neuropathies, while its beta subunit promotes cancer metastasis through redox regulation and stress granule assembly. Researchers can leverage CRISPR knockout, point mutation, knock-in, and overexpression models to dissect its roles in health and disease. EDITGENE provides end-to-end services to support these investigations.
References
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- 2. Elpeleg O et al.. 2005. Deficiency of the ADP-forming succinyl-CoA synthase activity is associated with encephalomyopathy and mitochondrial DNA depletion.. Am J Hum Genet 76(6):1081-6 PMID: 15877282
- 3. Huang J et al.. 2019. ATP-specificity of succinyl-CoA synthetase from Blastocystis hominis.. Acta Crystallogr D Struct Biol 75(Pt 7):647-659 PMID: 31282474
- 4. Chen B et al.. 2026. NSUN2 Promotes Cancer Immune Evasion via Its Moonlighting Function Acting on Metabolic Reprogramming.. Cancer Commun (Lond) 46:0042 PMID: 42620795
- 5. Hiramatsu Y et al.. 2022. Complex hereditary peripheral neuropathies caused by novel variants in mitochondrial-related nuclear genes.. J Neurol 269(8):4129-4140 PMID: 35235001
- 6. Pendleton AL et al.. 2020. Lower oxygen consumption and Complex I activity in mitochondria isolated from skeletal muscle of fetal sheep with intrauterine growth restriction.. Am J Physiol Endocrinol Metab 319(1):E67-E80 PMID: 32396498
- 7. Huang X et al.. 2017. Succinyl-CoA synthetase (SUCLA2) deficiency in two siblings with impaired activity of other mitochondrial oxidative enzymes in skeletal muscle without mitochondrial DNA depletion.. Mol Genet Metab 120(3):213-222 PMID: 27913098
- 8. Wider de Xifra EA et al.. 1978. Porphyrin biosynthesis: immobilized enzymes and ligands. VI. Studies on succinyl CoA synthetase from cultured soya bean cells.. Biochim Biophys Acta 523(1):245-9 PMID: 564714
